Washington: US President Barack Obama has called Doctors Without Borders to apologize to it for the US mistaken bombing of the organisation-run hospital in Afghanistan, White House said on Wednesday.

Obama's apology came four days after at least 22 people, including 12 staff with Doctors Without Borders, also known as Medecins Sans Frontieres (MSF), were killed in the US airstrike in Kunduz province in Afghanistan on Saturday.